diff --git a/src/cmd/asm/internal/arch/arch.go b/src/cmd/asm/internal/arch/arch.go
index c14a13cdb13..f9436cb7f22 100644
--- a/src/cmd/asm/internal/arch/arch.go
+++ b/src/cmd/asm/internal/arch/arch.go
@@ -162,8 +162,6 @@ func archX86(linkArch *obj.LinkArch) *Arch {
 	instructions["MOVDQ2Q"] = x86.AMOVQ
 	instructions["MOVNTDQ"] = x86.AMOVNTO
 	instructions["MOVOA"] = x86.AMOVO
-	instructions["PF2ID"] = x86.APF2IL
-	instructions["PI2FD"] = x86.API2FL
 	instructions["PSLLDQ"] = x86.APSLLO
 	instructions["PSRLDQ"] = x86.APSRLO
 	instructions["PADDD"] = x86.APADDL
diff --git a/src/cmd/internal/obj/x86/a.out.go b/src/cmd/internal/obj/x86/a.out.go
index 12eaa90bf6f..28c973b4a83 100644
--- a/src/cmd/internal/obj/x86/a.out.go
+++ b/src/cmd/internal/obj/x86/a.out.go
@@ -644,23 +644,6 @@ const (
 	APEXTRD
 	APEXTRQ
 	APEXTRW
-	APFACC
-	APFADD
-	APFCMPEQ
-	APFCMPGE
-	APFCMPGT
-	APFMAX
-	APFMIN
-	APFMUL
-	APFNACC
-	APFPNACC
-	APFRCP
-	APFRCPI2T
-	APFRCPIT1
-	APFRSQIT1
-	APFRSQRT
-	APFSUB
-	APFSUBR
 	APHADDD
 	APHADDSW
 	APHADDW
@@ -691,7 +674,6 @@ const (
 	APMOVZXWD
 	APMOVZXWQ
 	APMULDQ
-	APMULHRW
 	APMULHUW
 	APMULHW
 	APMULLD
@@ -722,7 +704,6 @@ const (
 	APSUBUSB
 	APSUBUSW
 	APSUBW
-	APSWAPL
 	APUNPCKHBW
 	APUNPCKHLQ
 	APUNPCKHQDQ
@@ -761,11 +742,6 @@ const (
 	AUNPCKLPS
 	AXORPD
 	AXORPS
-
-	APF2IW
-	APF2IL
-	API2FW
-	API2FL
 	ARETFW
 	ARETFL
 	ARETFQ
diff --git a/src/cmd/internal/obj/x86/anames.go b/src/cmd/internal/obj/x86/anames.go
index 1875eae4181..3c3bc03622e 100644
--- a/src/cmd/internal/obj/x86/anames.go
+++ b/src/cmd/internal/obj/x86/anames.go
@@ -593,23 +593,6 @@ var Anames = []string{
 	"PEXTRD",
 	"PEXTRQ",
 	"PEXTRW",
-	"PFACC",
-	"PFADD",
-	"PFCMPEQ",
-	"PFCMPGE",
-	"PFCMPGT",
-	"PFMAX",
-	"PFMIN",
-	"PFMUL",
-	"PFNACC",
-	"PFPNACC",
-	"PFRCP",
-	"PFRCPI2T",
-	"PFRCPIT1",
-	"PFRSQIT1",
-	"PFRSQRT",
-	"PFSUB",
-	"PFSUBR",
 	"PHADDD",
 	"PHADDSW",
 	"PHADDW",
@@ -640,7 +623,6 @@ var Anames = []string{
 	"PMOVZXWD",
 	"PMOVZXWQ",
 	"PMULDQ",
-	"PMULHRW",
 	"PMULHUW",
 	"PMULHW",
 	"PMULLD",
@@ -671,7 +653,6 @@ var Anames = []string{
 	"PSUBUSB",
 	"PSUBUSW",
 	"PSUBW",
-	"PSWAPL",
 	"PUNPCKHBW",
 	"PUNPCKHLQ",
 	"PUNPCKHQDQ",
@@ -710,10 +691,6 @@ var Anames = []string{
 	"UNPCKLPS",
 	"XORPD",
 	"XORPS",
-	"PF2IW",
-	"PF2IL",
-	"PI2FW",
-	"PI2FL",
 	"RETFW",
 	"RETFL",
 	"RETFQ",
diff --git a/src/cmd/internal/obj/x86/asm6.go b/src/cmd/internal/obj/x86/asm6.go
index 4ed1d8790bc..a06d3097ad5 100644
--- a/src/cmd/internal/obj/x86/asm6.go
+++ b/src/cmd/internal/obj/x86/asm6.go
@@ -184,7 +184,6 @@ const (
 	Zm2_r
 	Zm_r_xm
 	Zm_r_i_xm
-	Zm_r_3d
 	Zm_r_xm_nr
 	Zr_m_xm_nr
 	Zibm_r /* mmx1,mmx2/mem64,imm8 */
@@ -753,10 +752,6 @@ var yxrrl = []ytab{
 	{Yxr, Ynone, Yrl, Zm_r, 1},
 }
 
-var ymfp = []ytab{
-	{Ymm, Ynone, Ymr, Zm_r_3d, 1},
-}
-
 var ymrxr = []ytab{
 	{Ymr, Ynone, Yxr, Zm_r, 1},
 	{Yxm, Ynone, Yxr, Zm_r_xm, 1},
@@ -1085,7 +1080,6 @@ var optab =
 	{ACVTPD2PS, yxm, Pe, [23]uint8{0x5a}},
 	{ACVTPS2PL, yxcvm1, Px, [23]uint8{Pe, 0x5b, Pm, 0x2d}},
 	{ACVTPS2PD, yxm, Pm, [23]uint8{0x5a}},
-	{API2FW, ymfp, Px, [23]uint8{0x0c}},
 	{ACVTSD2SL, yxcvfl, Pf2, [23]uint8{0x2d}},
 	{ACVTSD2SQ, yxcvfq, Pw, [23]uint8{Pf2, 0x2d}},
 	{ACVTSD2SS, yxm, Pf2, [23]uint8{0x5a}},
@@ -1303,26 +1297,6 @@ var optab =
 	{APEXTRB, yextr, Pq, [23]uint8{0x3a, 0x14, 00}},
 	{APEXTRD, yextr, Pq, [23]uint8{0x3a, 0x16, 00}},
 	{APEXTRQ, yextr, Pq3, [23]uint8{0x3a, 0x16, 00}},
-	{APF2IL, ymfp, Px, [23]uint8{0x1d}},
-	{APF2IW, ymfp, Px, [23]uint8{0x1c}},
-	{API2FL, ymfp, Px, [23]uint8{0x0d}},
-	{APFACC, ymfp, Px, [23]uint8{0xae}},
-	{APFADD, ymfp, Px, [23]uint8{0x9e}},
-	{APFCMPEQ, ymfp, Px, [23]uint8{0xb0}},
-	{APFCMPGE, ymfp, Px, [23]uint8{0x90}},
-	{APFCMPGT, ymfp, Px, [23]uint8{0xa0}},
-	{APFMAX, ymfp, Px, [23]uint8{0xa4}},
-	{APFMIN, ymfp, Px, [23]uint8{0x94}},
-	{APFMUL, ymfp, Px, [23]uint8{0xb4}},
-	{APFNACC, ymfp, Px, [23]uint8{0x8a}},
-	{APFPNACC, ymfp, Px, [23]uint8{0x8e}},
-	{APFRCP, ymfp, Px, [23]uint8{0x96}},
-	{APFRCPIT1, ymfp, Px, [23]uint8{0xa6}},
-	{APFRCPI2T, ymfp, Px, [23]uint8{0xb6}},
-	{APFRSQIT1, ymfp, Px, [23]uint8{0xa7}},
-	{APFRSQRT, ymfp, Px, [23]uint8{0x97}},
-	{APFSUB, ymfp, Px, [23]uint8{0x9a}},
-	{APFSUBR, ymfp, Px, [23]uint8{0xaa}},
 	{APHADDD, ymmxmm0f38, Px, [23]uint8{0x0F, 0x38, 0x02, 0, 0x66, 0x0F, 0x38, 0x02, 0}},
 	{APHADDSW, yxm_q4, Pq4, [23]uint8{0x03}},
 	{APHADDW, yxm_q4, Pq4, [23]uint8{0x01}},
@@ -1353,7 +1327,6 @@ var optab =
 	{APMOVZXWD, yxm_q4, Pq4, [23]uint8{0x33}},
 	{APMOVZXWQ, yxm_q4, Pq4, [23]uint8{0x34}},
 	{APMULDQ, yxm_q4, Pq4, [23]uint8{0x28}},
-	{APMULHRW, ymfp, Px, [23]uint8{0xb7}},
 	{APMULHUW, ymm, Py1, [23]uint8{0xe4, Pe, 0xe4}},
 	{APMULHW, ymm, Py1, [23]uint8{0xe5, Pe, 0xe5}},
 	{APMULLD, yxm_q4, Pq4, [23]uint8{0x40}},
@@ -1395,7 +1368,6 @@ var optab =
 	{APSUBUSB, yxm, Pe, [23]uint8{0xd8}},
 	{APSUBUSW, yxm, Pe, [23]uint8{0xd9}},
 	{APSUBW, yxm, Pe, [23]uint8{0xf9}},
-	{APSWAPL, ymfp, Px, [23]uint8{0xbb}},
 	{APUNPCKHBW, ymm, Py1, [23]uint8{0x68, Pe, 0x68}},
 	{APUNPCKHLQ, ymm, Py1, [23]uint8{0x6a, Pe, 0x6a}},
 	{APUNPCKHQDQ, yxm, Pe, [23]uint8{0x6d}},
@@ -3533,15 +3505,6 @@ func doasm(ctxt *obj.Link, p *obj.Prog) {
 				ctxt.Andptr[0] = byte(p.To.Offset)
 				ctxt.Andptr = ctxt.Andptr[1:]
 
-			case Zm_r_3d:
-				ctxt.Andptr[0] = 0x0f
-				ctxt.Andptr = ctxt.Andptr[1:]
-				ctxt.Andptr[0] = 0x0f
-				ctxt.Andptr = ctxt.Andptr[1:]
-				asmand(ctxt, p, &p.From, &p.To)
-				ctxt.Andptr[0] = byte(op)
-				ctxt.Andptr = ctxt.Andptr[1:]
-
 			case Zibm_r, Zibr_m:
 				for {
 					tmp1 := z